Halve and stone the plums and place in a saucepan with 80g sugar. Cover with a lid and cook for 5-10 minutes on medium heat, or until just cooked and soft. Allow to cool, then pass through a sieve, discarding the skins.

Put cream, milk and scraped vanilla bean in a heavy based pot and gently bring to a simmer. Turn off heat and allow to infuse for 20 minutes.

In a bowl, whisk egg yolks and remaining sugar until combined. Heat the cream again, then whisk in the yolks. Pour the mixture into a clean pot and put on a moderate heat. Use a wooden spoon to stir constantly, cooking the mixture until it thickens slightly and coats the back of the spoon.

Strain into a cold bowl and cool completely in the fridge before stirring in the plum puree and churning in an ice-cream maker, according to manufacturer's instructions.